I have this EXACT same problem. I moved and set up my internet with a different provider, and originally even had a different name for the wifi but still got the error “There was a problem connecting to the network”, and it wouldn’t let me click on the network to type a password in or even forget it.
I tried to connect it to my hotspot but still got the same error. When trying neighbours wifis I am promoted to put a password, but don’t even have that option for my wifi, it automatically goes to the error screen.
I even tried to restore and reset the Apple TV but still getting the same error.
It’s advised to update software but how do I do that without being able to connect to the internet.
OP is you have solved it plz let me know I would appreciate it!